Japanese Patent Application Disclosure No. 61-181554 discloses a centrifugal oil separation apparatus which comprises a rotatable cylinder including a plurality of small apertures for drawing frying oil, and a rotary chip receiving member for temporally storing the frying oil, the rotary chip receiving member being located coaxially to the cylinder and including a central recess on the internal bottom wall thereof. Oily chips (e.g. small waste pieces produced from stamping) are thrown into the rotatable cylinder through the top opening thereof and temporally stored on the rotary chip receiving member. Thereafter, the chip receiving member is rotated such that the oily chips are moved from the rotary chip receiving member to the inner wall of the rotatable cylinder under the action of a centrifugal force created during rotation of the chip receiving member. The oily chips moved onto the inner wall of the rotating cylinder are urged against that inner wall under the action of a centrifugal force created during rotation of the cylinder. In such a manner, oil can be separated from the oily chips under the influence of the centrifugal force. After completion of the separating operation, the rotation of the cylinder is stopped. As a result, the chips will drop from the inner wall of the cylinder under gravity.
Japanese Utility Model Disclosure No. 60-168558 describes a centrifugal hydroextractor for separating water and/or oil from various industrial components or works such as bolts, rivets or the like. The centrifugal hydroextractor comprises a rotary cylindrical member which has top and bottom openings and an intermediate portion having a diameter larger than those of the top and bottom portions of the cylinder. When the cylindrical member is being rotated, the works placed therein are moved from the central conical-shaped guide member to the inner wall of the intermediate portion of the cylindrical member under the action of centrifugal force. Thus, water can be extracted from the works the inner wall of the cylindrical member. When the rotation of the cylindrical member is stopped, the works will drop from the inner wall of the cylindrical member onto a work sliding surface located below the cylindrical member under gravity. The works can be discharged out of the centrifugal hydroextractor through the work sliding surface.
In any event, the prior art centrifuges are adapted to rapidly move the oily parts from the central position in the rotating cylinder to the inner wall thereof. Thus, the fragile parts such as fried foodstuffs may lie easily damaged.
In the prior art centrifuges, further, the foodstuffs and works may be firmly deposited on the inner wall of the rotating cylinder, depending on the property of oil to be separated and the shape and property of the foodstuffs and works. Even if the cylinder is stopped, the foodstuffs or works may not drop from the inner wall of the cylinder under gravity. Particularly, if foodstuffs to be centrifugally treated are vacuum fried products, clogging was created by the fried products depositing on the inner wall of the cylinder. If the fried products are subjected to centrifugal force many times as they deposit on the inner wall of the cylinder, the fried products will be cooled and set too much, resulting in fragile products which may be easily damaged. Such fragile products may be highly different from the other products in the amount of oil contained therein.
In view of these problems in the prior art centrifuges, it is an object of the present invention to provide a centrifugal separating apparatus which can less damage matters subjected to the centrifugal action.
Another object of the present invention is to provide a centrifugal separating apparatus in which after fried products or oily works have been subjected to the centrifugal action, they can reliably drop the inner wall of the rotating member.